Dry sprinkler arrangements

ABSTRACT

In the particular embodiments described in the specification, a dry sprinkler has a tube-like section with a sprinkler head at one end and a threaded portion to be received in a water supply line at the opposite end and it includes an internal support structure extending between a sealing plug in the end to be received in the water supply line and a cap in the sprinkler head which is supported by a thermally responsive structure. In one embodiment, the support structure includes a rod on which the sealing plug is mounted at one end and having a cap-engaging tip at the opposite end which is shaped to facilitate the flow of water from the sprinkler head toward a deflector, the rod being spaced from the tube-like section by two guide members, one of which acts as a stop for motion of the structure toward the sprinkler head and the other which engages a spring urging the structure toward the sprinkler head. In other embodiments, a spacer is inserted between the end of the rod and the cap in the sprinkler head and a separate rod tip may be inserted between the rod and the spacer. In a further embodiment, an inner tube extends between the cap and the sealing plug and is shaped with spaced triangular tips to support the sealing plug in the unactuated condition and a water supply line connection which is coupled to the water supply line has a lateral cavity recess to receive the sealing plug out of the path of water flowing through the inner tube when the sprinkler is actuated.

REFERENCE TO A RELATED APPLICATION

This application is a division of application Ser. No. 08/712,274 filedSep. 11, 1996, now U.S. Pat. No. 5,775,431.

BACKGROUND OF THE INVENTION

This invention relates to dry sprinkler arrangements for fire protectionsystems and, more particularly, to new and improved dry sprinklerarrangements which more effectively convey water to a sprinklerdeflector.

Conventional dry sprinklers for fire protection systems include a pipeconnected at one end to a sprinkler head having a thermally responsivedevice and a deflector and at the other end to a water supply line andthey include a valve or sealing plug at the end of the pipe joined tothe water supply line to prevent pressurized air, nitrogen or water fromentering the pipe until the thermally responsive device in the sprinklerhead has been actuated. Such dry sprinkler arrangements usually includea rod or tube within the pipe separating the sprinkler head from thesealing plug to retain the plug in its sealing position until thesprinkler has been actuated. Following actuation, the inner rod or tubemoves away from the supply line and projects out of the pipe toward thesprinkler head deflector, partially interfering with the flow of watertoward the deflector. Moreover, after actuation the plug may be retainedwithin the pipe in a position which also interferes with the flow ofwater through the pipe toward the sprinkler head.

Certain prior art dry sprinkler arrangements have been proposed toalleviate these problems, but they often require complex and potentiallyunreliable structural arrangements. For example, U.S. Pat. Nos.2,180,258, 3,061,015, 3,080,000, 4,417,626, and 4,228,858 disclose drysprinkler arrangements in which a loose plug releasably held in asealing position at the end of the dry sprinkler adjacent to the watersupply is intended to pass through the dry sprinkler and be ejected fromthe sprinkler after actuation. These arrangements require releasableplug-holding elements, such as balls or the like, which are designed tomove away from a plug-supporting position and to be ejected through thedry sprinkler with the plug when the sprinkler is actuated.

U.S. Pat. No. 5,188,185, on the other hand, discloses a dry sprinklerarrangement having a sealing plug at the end adjacent to the watersupply line which is pivotally mounted on the projecting ends of a yokemember supported from the sprinkler head by an internal tube extendingthrough the dry sprinkler. A spring surrounding the yoke member extendsbetween projecting tabs on the yoke member and the adjacent end of awater supply line connection at the water pipe to urge the yoke membertoward the sprinkler head. The water supply line connection has aradially enlarged opening providing room for the plug to be rotated 90°on the yoke when the sprinkler is actuated so as to displace the plugfrom the path of water flowing through the sprinkler head. Such priorart systems are complex in structure and expensive to manufacture.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a drysprinkler arrangement which overcomes the disadvantages of the priorart.

Another object of the invention is to provide a dry sprinklerarrangement having a sealing plug support structure which avoidsinterference with the flow of water through the sprinkler when actuated.

A further object of the invention is to provide a dry sprinklerarrangement having a sealing plug support structure which facilitatesthe flow of water toward a sprinkler deflector following actuation ofthe sprinkler.

These and other objects of the invention are attained by providing a drysprinkler which includes a tube-like section having a sprinkler headwith a deflector at one end and having an internal support structure forsupporting a sealing plug to seal the opposite end which seal isreleasable upon actuation of the sprinkler head and including aninternal spring urging the internal support structure toward thesprinkler head, wherein the internal support structure is constructed tofacilitate the flow of water through the pipe and toward the deflectorat the sprinkler head upon actuation of the sprinkler.

According to one embodiment, the internal support structure includes asupport member extending through the pipe and having longitudinallyspaced guides for guiding the support member generally centrallytherein, one of the guides constituting a stop for stopping motion ofthe support member in the direction toward the sprinkler head andanother of the guides engaging one end of the internal spring. In thisembodiment, the end of the support member adjacent to the sprinkler headis shaped to minimize obstruction to water flowing toward the deflectorand the opposite end carries a plug for sealing the dry sprinkler fromthe water supply line, the support member being arranged to displace thesealing plug upon actuation of the sprinkler and to facilitate the flowof water through the pipe. An alternative arrangement includes a spacer,ejectable upon actuation of the sprinkler, by which the end of thesupport member is normally supported from a cap held in place by asprinkler actuation arrangement. If desired, the end of the supportmember engaging the cap or the spacer may be separable from theremainder of the support member.

According to a further embodiment, the support member abuts the sealingplug and is shaped so as to displace the plug laterally from the waterflow path when the sprinkler is actuated. In this embodiment, thetube-like section is mounted to the water supply line connection whichis engageable with the water supply line and which has a lateral recessto receive the displaced sealing plug out of the water flow path uponactuation and the end of the plug support member has tapered endportions to divert the plug into the recess when the sprinkler isactuated. If desired, the support member may be supported from the capand the sprinkler actuating mechanism by a split ring which is ejectablefrom the pipe when the sprinkler is actuated, thus clearing the waterflow path.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention will be apparent from areading of the following description in conjunction with theaccompanying drawings, in which:

FIG. 1 is a longitudinal sectional view illustrating a representativeembodiment of the invention in the unactuated condition;

FIG. 2 is a longitudinal sectional view illustrating the embodiment ofFIG. 1 in the actuated condition;

FIG. 3 is a fragmentary longitudinal sectional view illustrating amodification of the embodiment of FIG. 1 in the unactuated condition;

FIG. 4 is a similar view illustrating the modification of FIG. 3 in theactuated condition;

FIG. 5 is a partial longitudinal sectional view illustrating a furthermodification of the embodiment of FIG. 1;

FIG. 6 is a similar view illustrating the modification of FIG. 5 in theactuated condition;

FIGS. 7A-7D illustrate typical guide members useful in the embodimentsof FIGS. 1-6;

FIG. 8 is a longitudinal sectional view illustrating a furtherembodiment of the invention in the unactuated condition;

FIG. 9 is a similar view illustrating the embodiment of FIG. 8 in theactuated condition;

FIG. 10 is a fragmentary sectional view taken along the line X--X ofFIG. 8 and looking in the direction of the arrows;

FIG. 11 is a fragmentary sectional view of the embodiment shown in FIG.8 illustrating the operation of that embodiment; and

FIG. 12 is a fragmentary longitudinal sectional view illustrating amodification of the embodiment shown in FIG. 8.

FIG. 13 is a longitudinal sectional view illustrated still anotherembodiment of the invention in the unactuated condition; and

FIG. 14 is a view similar to that of FIG. 13 illustrating the embodimentin the actuated condition.

DESCRIPTION OF PREFERRED EMBODIMENTS

In the typical embodiment of the invention shown in FIGS. 1 and 2, a drysprinkler 10 includes a tube-like section 12 having an externallythreaded end 14 to be connected to a water supply line (not shown) andhaving internal threads at the opposite end 16 to receive a conventionalsprinkler head 18. If desired, the sprinkler head may be joined to thetube-like section in any other appropriate manner. The sprinkler head 18has an internal passage 20 communicating with the interior of the pipe12 and a cap 22 covers the end of the passage 20. The cap 22 is held inposition by one end of a conventional thermally responsive structure 24which is supported at the opposite end by a boss 25 formed at thejunction of two arms 26 and 28 and a conventional deflector 30 ismounted in the usual manner on the boss 25.

Centrally positioned within the tube-like section 12 by upper and lowerguide members 32 and 34 is a support rod 36 having a sealing plug 38affixed at its upper end 39. The sealing plug 38 has a circumferentialsealing ring 40 which is compressed between the plug 38 and the surfaceof an opening 41 in a disc 42 which is affixed in the upper end of thetube-like section 12 for example, by pressing and staking. The lower end44 of the support rod 36 engages the cap 22 and a compression spring 46extends between the upper guide member 32 and the inner end of the disc42 to urge the support rod 36 downwardly against the cap 22. Thus, thesealing plug 38 is held in its sealing position as long as the cap 22 issupported in its position at the end of the passage 20 by the thermallyresponsively structure 24.

The guide members 32 and 34, which have radial arms spaced by angularopenings as shown in FIGS. 7A-7D, are mounted in fixed position on therod 36 for example, by pressing and staking at 37 and the upper guidemember 32 is affixed at a position spaced from the disc 42 sufficientlyto permit the compression spring 46 to be compressed between them. Thelower guide member 34 is affixed to the support rod 36 at a positionspaced from the inner end 48 of the sprinkler head 18 by a distancesufficient to permit the support rod 36 and the sealing plug 38 to movedownwardly within the pipe 12 upon actuation far enough to provide anundiminished cross-section for flow of water through the opening 41 inthe disc 42 and through the pipe 12 and the passage 20 withoutobstruction when the sprinkler has been actuated.

When the temperature in the vicinity of the sprinkler head 18 has beenraised to a predetermined elevated temperature, the thermally responsiveelement 24 collapses, permitting the spring 46 to urge the end 44 of thesupport rod 36 downwardly through the end of the passage 20 forcing thecap 22, as well as the components of the thermally responsive structure24, away from the sprinkler head 18. At the same time, the sealing plug38 moves downwardly away from the passage 41 as shown in FIG. 2 untilthe lower guide member 34 engages the inner end 48 of the sprinklerhead. The upper end 14 of the pipe 12 is thus open to water from thewater line to which it is connected and the plug 38 is spaced from thedisc 42 far enough to permit unobstructed flow of water through theopening 41 and around the plug and then through the openings between theradial arms in the guide members 32 and 34 and through the passage 20toward the deflector 30 as illustrated by the arrows in FIG. 2.

In order to facilitate the flowing of water through the tube-likesection 12 toward the deflector 30 for distribution throughout the areato be protected, the lower end 44 of the support rod 36 has a surface 50which tapers inwardly toward its tip from a location within the passage20 so that the water flowing through the passage 20 continues in thedirection toward the deflector 30 and is not diverted away from thedeflector by the lower end 44 when it protrudes downwardly from the endof the passage 20 as shown in FIG. 2.

FIGS. 7A-7D illustrate typical arrangements for the guide members 32 and34. In FIG. 7A the guide member has a central hub 52 with an opening 54to receive the support rod 36 and includes three arms 56 projectingradially at uniform angles about the periphery of the hub 52, each ofthe arms 56 having a substantially oval or elliptical cross-section,thus providing three angular openings of about 120° between the arms forwater passing through the pipe. The guide member arrangement shown inFIG. 7B has a cylindrical hub 58 with a central opening 60 to receivethe rod 36 and three radial arms 62 of rectangular cross-section,providing a structure which is simple to fabricate by machining ormolding. The guide member shown in FIG. 7C is similar to that of FIG.7B, except that it has four radial arms 62 disposed at equal anglesabout the periphery of the hub 58, thereby providing four angularopenings of about 90° for passage of water through the tube-likesection. Finally, the guide member shown in FIG. 7D is similar to thatof FIG. 7B but its hub 59 has an internal threaded opening 61 and itsthree radial arms 64 have axial projections 66 which extend beyond theend surface 68 of the hub 59 and include edge surfaces 70 which taperinwardly toward the end surface 68 of the hub 59. The length of theprojections 66 beyond the end surface 68 is selected to assure anunrestricted flow of water between the hub 59 and the inner end 48 ofthe sprinkler head when the rod 36 is in the actuated condition as shownin FIG. 4.

With the dry sprinkler arrangement shown in FIGS. 1 and 2, a simple andinexpensive structure is provided which effectively conducts water fromthe upper end through the tube-like section 12 and toward the deflector30 without requiring any parts to pass through the tube and be ejectedthrough the sprinkler passage or parts which must be articulated orlinked by a pivoting arrangement or the like within the tube section.

In the modified form illustrated in FIG. 3, a dry sprinkler arrangement70 includes a tube section 72 and a sprinkler head 74 affixed to thetube at its lower end by pins 76 and having a passage 78 covered by acap 80 which is held in place by one end of a thermally responsiveelement 82. At its opposite end, the thermally responsive element 82engages boss 84 which is formed at the junction of two spaced arms 86and 88 and supports a deflector 90.

Within the tube section 72, a support rod 92 has its lower end threadedinto the upper end of the central opening 94 of a guide member 96 of thetype shown in FIG. 7D having axially projecting ends 97, a separate tipmember 98 being threaded into the lower end of the opening 94. The tipmember 98 has a tapering external surface 100 for facilitating themaximum flow of water through the passage 78 toward the deflector 90without causing the water to be diverted outwardly away from thedeflector 90 as described above with respect to FIGS. 1 and 2. In thiscase the lower end 102 of the tip member 98 is supported by a spacer 104which has a central dimple 106 receiving the end 102 of the tip member98.

When the sprinkler is actuated by elevation of the thermally responsivemember 82 above its operating temperature, the compression spring 46 atthe upper end of the support rod 92 urges the support rod downwardly,forcing the cap 80 and the spacer 104 away from the passage 78. Thesupport rod 92 then moves downwardly until the axially projecting ends97 of the radial arms of the lower guide member 96 engage the inner end108 of the sprinkler head 74, positioning the tapered surface 100 of thetip member 98 within the passage 102 so as to facilitate the flow ofwater through the passage in a direction toward the deflector 90 asillustrated by the arrows in FIG. 4.

As in the embodiment described previously, this arrangement permitswater to be conducted through the tube section in a substantiallyunobstructed manner and facilitates the flow of water toward thedeflector 90 without requiring any parts to pass through the tubesection or requiring hinged or articulated parts within the tube.

In the further modification shown in FIGS. 5 and 6, a dry sprinkler 110includes a tube-like section 112 having a sprinkler head 114 threadedlymounted at the lower end. In this embodiment a support rod 92 carriesguide members 96 having radial arms with axial projections 97 of thesame type described above and a spacer 104 of the type previouslydescribed with respect to FIGS. 3 and 4 is interposed between thesupport rod and a cap 115 which covers a sprinkler passage 116. In thiscase, however, a separable rod tip 116 has one end 118 received in thedimple 106 of the spacer 104 and the other end 120 inserted withclearance into the lower end of the threaded opening 94 in the guidemember, the entire structure being supported by the cap 115 as long as athermally responsive release member 122 remains unactuated.

Upon actuation, as shown in FIG. 6, the separable tip 117 is ejectedfrom the sprinkler head along with the spacer 104 and the cap 115,permitting water to flow in an unobstructed manner through the sprinklerpassage 116 and facilitating flow of water toward the deflector 124 asshown by the arrows in FIG. 6.

In the further embodiment of the invention illustrated in FIGS. 8-11, adry sprinkler arrangement 130 includes a tube-like section 132 affixedby pressure-formed connections 134 to a sprinkler head 136 at one endand to a water supply line connection 138 at the opposite end. The watersupply line connection 138 has external threads 140 for connection to awater supply line and has an internal ending formed with a centralopening 142 in which a sealing plug 144 having a peripheral gasket 146is supported in a sealing relationship. The water supply line connection138 also has a passage 148 at the opposite end of similar diameter tothe opening 142. Between the opening 142 and the passage 148 the watersupply line connection 138 is formed with a cavity 150 having a diameterwhich is larger than that of the opening 142 and the passage 148 by anamount at least equal to the axial length of the sealing plug 144.

Within the tube section 132 an inner tube 152 extends slidably throughthe opening 148 in the water supply line connection 138 and through acorresponding opening 154 in the sprinkler head 136 and the lower end ofthe tube 152 engages a cap 156 which is supported in position in thesprinkler head 136 by a thermally responsive structure 158. In addition,a deflector 160 is mounted in the usual manner at the outer end of thesprinkler head.

In order to support the sealing plug 144 in its sealing position in theopening 142, the inner tube 152 is formed at the upper end with twolaterally spaced triangular tips 162 which, as best seen in FIG. 10,project from opposite sides of the tube and engage the inner surface 164of the sealing plug 144 to support it in position. As shown in FIG. 10passages are provided between the tips 162 to permit water to flow fromthe cavity 150 into the inner tube 152. Moreover, each of the tips 162has an opening 165 providing an additional passage for water to flowfrom the cavity 150 into the inner tube 131. At a location spaced fromthe water supply line connection the inner tube 152 is formed withoutwardly projecting spring stop tabs 166 and a compression spring 168is compressed between the tabs 166 and the inner end 170 of the watersupply line connection 138 so as to urge the inner tube 152 downwardlytoward the cap 156. Two further tabs 171, which project outwardly fromthe lower end of the inner tube 152 at locations normally spaced fromthe inner end 172 of the sprinkler head 136, are engageable with thesprinkler head when the sprinkler has been actuated, thereby providing astop for the downward motion of the inner tube following actuation. Asshown in FIGS. 8-10, the tabs 166 and 171 are portions bent outwardlyfrom the wall of the tube 152, leaving openings in the tube wall whichlead to a further flow path for water outside the tube 152 and insidethe tube 132 between the water supply line connection 138 and thesprinkler head 136.

Upon actuation of the sprinkler by collapse of the thermally responsivestructure 158, the spring 168 forces the inner tube 152 downwardly,ejecting the structure 158 and the cap 156 from the sprinkler head andmoving downwardly until the outwardly projecting tabs 171 engage theinner end 172 of the sprinkler head as shown in FIG. 9. Successivepositions of the upper end of the inner tube 152 during its downwardmotion are illustrated in the left and right halves, respectively, ofFIG. 11 and as shown in dotted lines the sealing plug 144, no longersupported by the upper ends of the triangular tips 162, tilts sidewardlyon the tips 162 and is guided by their sloping surfaces into a positionout of the water flow path in the side recess of the cavity 150. As aresult, as shown by the arrows in FIG. 9, water enters the inner tube152 by flowing through the passages between the projecting tips 162 andalso through the openings 165 in the walls of the tube communicatingbetween the cavity 150 and the interior of the tube. The water thusfollows an unobstructed path between the opening 142 in the installationhead 138 through the inner tube 152 and toward the deflector 160 at theouter end of the sprinkler head 136.

In the modified form of the invention shown in FIG. 12, a dry sprinkler172 is the same as that shown in FIGS. 8-11, except that the inner tubeincludes a conical tip part 174 having a projecting flange 176 to engagea compression spring 178 which is seated at the opposite end against theinner end 180 of a water supply line connection 182. The inner tube alsohas a lower part 184 which is the same as the lower part of the innertube 152 of the embodiment of FIGS. 8-11. In this embodiment, theconical tip 174 has a plurality of lateral openings 186 providing atotal water flow area large enough to permit passage of all of the waterreceived through the opening 142 in the water supply line connection182. The water supply connection also has an internal cavity 188 whichslopes inwardly toward the conical tip 174 to guide the tip as it isactuated away from the supporting seal 144.

In a further modification shown in FIGS. 13 and 14, a split ringconsisting of two half rings 190 and 192 is interposed between the lowerend of the inner tube 152 and the cap 156, the structure being otherwisethe same as that described in connection with FIGS. 8-11. In this case,as seen in FIG. 14, the split ring parts 190 and 192 separate when thesprinkler is actuated and are therefore ejected from the sprinkler headalong with the cap 156 and the thermally responsive structure 158. As aresult, the inner tube 152 does not project beyond the passage 154 inthe sprinkler head when the sprinkler is actuated, thereby avoidinginterference with the flow of water through the inner tube 152 towardthe deflector 160.

Although the invention has been described herein with reference tospecific embodiments, many modifications and variations therein willreadily occur to those skilled in the art. Accordingly, all suchvariations and modifications are included within the intended scope ofthe invention.

I claim:
 1. A dry sprinkler comprising a tube section, a sprinkler headhaving a deflector mounted at one end of the tube section, a watersupply line connection at the other end of the tube section having anopening to receive water from a water supply line, a sealing plugnormally positioned in the opening to prevent pressurized air or waterfrom entering the tube section from a water supply line, a sealing plugsupport structure extending through the tube section, and a thermallyresponsive structure in the sprinkler head arranged to maintain thesealing plug support structure in position to support the sealing plugin its sealing position and to permit the sealing plug support structureto move toward the sprinkler head, releasing the sealing plug from itssealing position, in response to an elevated temperature condition,wherein the sealing plug support structure includes a rod and a spacerbetween the rod and the thermally responsive structure and wherein therod has a separable tip which engages the spacer and is ejectable uponactuation of the sprinkler.
 2. A dry sprinkler comprising a tubesection, a sprinkler head having a deflector mounted at one end of thetube section, a water supply line connection at the other end of thetube section having an opening to receive water from a water supplyline, a sealing plug normally positioned in the opening to preventpressurized air or water from entering the tube section from a watersupply line, a sealing plug support structure extending through the tubesection, and a thermally responsive structure in the sprinkler headarranged to maintain the sealing plug support structure in position tosupport the sealing plug in its sealing position and to permit thesealing plug support structure to move toward the sprinkler head,releasing the sealing plug from its sealing position, in response to anelevated temperature condition, wherein the sealing plug is separablefrom the sealing plug support structure and wherein the water supplyline connection has an internal cavity to receive the sealing plug at adisplaced position out of the path of water flowing through the tubesection upon actuation of the sprinkler.
 3. A dry sprinkler according toclaim 2 wherein the sealing plug support structure includes spacedtriangular tip portions normally retaining the sealing plug in sealingposition and effective upon actuation of the sprinkler to guide thesealing plug into its displaced position in the cavity.
 4. A drysprinkler according to claim 2 including a split ring interposed betweenthe sealing tube support structure and the thermally responsive supportstructure.
 5. A dry sprinkler according to claim 2 including apressure-formed connection joining the tube section to the sprinklerhead.
 6. A dry sprinkler according to claim 2 including a threadedconnection joining the tube section to the sprinkler head.
 7. A drysprinkler comprising a tube section, a sprinkler head having a deflectormounted at one end of the tube section, a water supply line connectionat the other end of the tube section having an opening to receive waterfrom a water supply line, a sealing member normally positioned in theopening to prevent pressurized air or water from entering the tubesection from a water supply line, a sealing member support structureextending through the tube section, and a thermally responsive structurein the sprinkler head arranged to maintain the sealing member supportstructure in position to support the sealing member in its sealingposition and to permit the sealing member support structure to movetoward the sprinkler head, releasing the sealing member from its sealingposition, wherein the sealing member support structure comprises aninternal tube slidably received at one end in the sprinkler head andhaving a projecting portion engaging and supporting the sealing memberat the opposite end and preventing the sealing member from passingthrough the internal tube; the inner tube having substantially the samecross-sectional area as the opening in the water supply line from theend engage the sealing member to an outlet end facing the deflector toprovide an unrestricted flow path from the water supply line to thedeflector.
 8. A dry sprinkler according to claim 7 wherein the sealingmember includes a circumferential seal between the sealing memberperiphery and the water supply line connection.
 9. A dry sprinkleraccording to claim 7 wherein the internal tube is formed with a firstprojecting tab providing a stop for motion of the tube toward thesprinkler head and a second projecting tab adjacent to the water supplyline connection and including a spring extending between the second taband the water supply line connection to urge the inner tube toward thesprinkler head.
 10. A dry sprinkler according to claim 7 including asplit ring arranged to be released upon activation of the thermallyresponsive structure interposed between the inner tube and the thermallyresponsive structure.
 11. A dry sprinkler according to claim 7 includinga pressure-formed connection joining the tube section and the sprinklerhead.
 12. A dry sprinkler according to claim 7 including a threadedconnection joining the tube section and the sprinkler head.
 13. A drysprinkler according to claim 7 including a pressure-formed connectionjoining the tube section and the water supply line connection.
 14. A drysprinkler according to claim 7 wherein the internal tube is spaced fromthe tube section and provides a further flow path for water outside theinternal tube between the water supply line connection and the sprinklerhead.
 15. A dry sprinkler according to claim 14 wherein the internaltube has outwardly projecting tabs providing openings for communicationbetween the interior of the internal tube and the further flow path.